Brownfields

Featured Project

BAYHORSE STATE PARK: Turning a Ghost Town into an Idaho State Park.

Alta completed the initial site investigation, collecting several hundred soil and water samples throughout the Townsite, associated mining operations, and ten miles of trail system connecting parcels. Following the site investigation, Alta completed a site-specific risk assessment, which was used as a basis for securing three Brownfields cleanup grants. Following receipt of the cleanup grants, Alta completed an Analysis of Cleanup Alternatives and Work Plan and designed and oversaw cleanup activities under the IDEQ’s Voluntary Cleanup Program.

Alta designed the site cleanup, including the tailings pile closure, repository construction, slag grading, bridge and parking lot construction, and a trail system linking the Townsite with the Upper Mines. We provided engineering and construction oversight for the Townsite, trail, and mine sites. Fencing and access restrictions, along with gravel and asphalt barriers in select locations, and stream enhancements and streambank protection were used to a safe environment for park visitors. The combination parking lot/slag repository serves as a trailhead for access to more than 100 miles of trails connecting various historic and recreational features in the Land of the Yankee Fork. The State Park is now opened to the public.

A subsequent project included designing an ATV trail and footpath system that linked the Townsite to the Skylark Mine and tramhouse areas, which are located on a steep hillside approximately 1,400 feet above the valley floor. Alta designed the trail system and remedial approach and oversaw construction, which included placing a physical barrier with a 12-inch layer of clean aggregate, steel cable fencing in key areas, and gabion structures to stabilize portions of the trail that cross loose talus slopes.